The present disclosure relates to materials for multilayer constructs useful for producing metabolite test strips. In particular, a non-conductive substrate layer, a metal conductor layer, and an oxidized Transparent Conducting Oxide (TCO) layer are provided to impart superior electrochemical response while maintaining desired mechanical properties, and will be described with particular reference thereto. However, it is to be appreciated that the present disclosure is also amenable to other like applications.
Metabolite test strips can be used in several applications, such as various metering devices for testing and/or determining certain characteristics and/or the presence of analytes in a specimen. For example, the test strips can be used as biosensors for measuring the amount of an analyte (e.g., glucose) in a biological fluid (e.g., blood). These biosensors use a redox enzyme (e.g., glutathione peroxidases (GPX), nitric oxide synthase (eNOS, iNOS, and nNOS), peroxiredoxins, super oxide dismutases (SOD), thioredoxins (Trx), and the like), as the biological component responsible for the selective recognition of the analyte of interest (e.g., glucose).
The biological fluid sample is introduced into the reaction chamber of the test strip and the test strip is connected to a measuring device such as a meter for analysis using the test strip's electrodes. The analyte in the sample undergoes a reduction/oxidation reaction at the working electrode (where the redox enzyme is located) while the measuring device applies a biasing potential signal through the electrodes of the test strip. The redox reaction produces an output signal in response to the biasing potential signal. The output signal usually is an electronic signal, such as potential or current, which is measured and correlated with the concentration of the analyte in the biological fluid sample.
Metabolite test strips of this type are made from multilayer constructs. An important feature of these multilayer constructs is that their materials have a reduced sensitivity to heat, humidity and degradation, while maintaining mechanical robustness and good electrical conductivity. Moreover, it would be advantageous to provide such materials at a reduced cost for expanding markets where utilization of these materials is rapidly expanding.
It would be desirable to develop new materials from which multilayer constructs can be built. These materials are desirably less affected by environmental factors such as air and water, and are mechanically robust while maintaining electrochemical preferentially. In addition, conductive layers in such test strips are typically made from expensive precious metals, such as silver, gold, palladium, or platinum. It would be desirable to develop new alloys that can be used in multilayer constructs that have superior electrochemical response and distinct mechanical advantages. It would also be desirable if such alloys did not include precious metals, which are costly.